1. Field of the Invention
The present invention relates generally to a film image capturing method, and more particularly to a film image capturing method of capturing frame images on a developed film with a line sensor.
2. Description of Related Art
Japanese Patent Provisional Publication No. 8-336071 discloses a conventional film image capturing method in which image data is captured with a line sensor from each of a plurality of frames on a continuous developed film, which is transported at a preset speed and is illuminated with a light source.
This film image capturing method includes the steps of performing a pre-scanning process for determining exposed conditions such as the brightness and white balance state of each frame before capturing fine image data from the frame, and performing a main scanning process for capturing fine image data from a desired frame under capturing conditions which are adjusted according to the exposed conditions of the desired frame determined in the pre-scanning process.
The method can include an index scanning process for capturing rough image data from each frame on the film under the capturing conditions which are adjusted according to the exposed conditions of each frame determined in the pre-scanning process, and thereby producing an index image showing the frames on the film. The index image, which is produced by the index scanning, is displayed on a screen of a TV monitor for example, and is used to interactively enter print order information with respect to each frame and information which is necessary for displaying a fine image of one frame at a time on the TV monitor, or the like.
The method can include a set-up process for capturing an image signal with the line sensor from a negative base area, which is not exposed at all, on the film, and adjusting a gain of an analog amplifier, etc. so that the image signal of the negative base area, which is output from the line sensor, can be a preset reference value.
A long time elapses before the intensity and spectral characteristics of light emitted from the light source (e.g. a fluorescent lamp) illuminating the film are stable after the light source is switched on. In the conventional image capturing method, the set-up process, the pre-scanning process and the index scanning process are performed after the light source reaches a predetermined stable state. For this reason, there is a problem in that the index image cannot be displayed rapidly, and thus, a variety of editing operations using the index image cannot be performed immediately.
There is another problem in that satisfactory image data cannot be captured if there are variations in the output level of the line sensor and/or the intensity of the light emitted from the light source.